List the SponsorBlock API in the "Requests To Other Places" section

[absidue]

Although those requests only happen if the user has enabled the SponsorBlock API, it's still worth listing it so that people know about it. An important thing to note here is that the domain that is used is configurable by the user, so we should mention that the domain for the requests will be different if they have changed it.

[efb4f5ff-1298-471a-8973-3d47447115dc]

We also have a domain for testing proxy connections that we should include.

[aleksejrs]

Note: this is about https://docs.freetubeapp.io/usage/privacy/#requests-to-other-places and https://docs.freetubeapp.io/usage/sponsorblock/